Effects of dietary taurine supplementation in low fish meal feed on growth, digestibility, intestinal enzyme activities of rice field eel (Monopterus albus)

In this study, the healthy rice field eels (Monopterus albus) with body mass of (25.03±0.02) g had been cultured for 10 weeks, and the effects of taurine on the growth, digestibility and intestinal enzyme activity of M. albus were studied. Four treatment groups with high-content fish meal (42%, FM), low-content fish meal (22%, T₀) and low-content fish meal diet supplemented with 0.2% (T_0.2) and 0.5% (T_0.5) taurine were set up, with five replicates in each group. The results show that compared with FM group, the weight gain rate, protein efficiency ratio, dry matter digestibility and protein digestibility of rice field eels decreased in T₀ group significantly (P<0.05), while the feed conversion ratio increased significantly (P<0.05). Adding an appropriate amount of taurine could increase the weight gain rate, protein efficiency ratio and dry matter digestibility of rice field eels, but reduce the feed coefficient (P<0.05). The weight gain rate, protein efficiency ratio and protein digestibility in T_0.5 group were approximate the same in T₀ group (P>0.05). Moreover, comparing with FM group, the intestinal creatine kinase, Na⁺-K⁺-ATPase, alkaline phosphatase, trypsin and lipase activities in T₀ group decreased significantly (P<0.05), but the activities of the aforementioned intestinal enzyme in T_0.2 group increased significantly (P<0.05). The activities of Na⁺-K⁺-ATPase, alkaline phosphatase, trypsin and lipase in T_0.5 group were higher than those in T₀ group, without significant difference (P>0.05). To sum up, 0.2% taurine supplementation in low-content fish meal feed can improve the growth performance, intestinal digestion and absorption function of rice field eel, but excess taurine (0.5%) has no obvious effect.